This invention relates to vibration dampers which are capable of absorbing and dissipating vibration energy in rotating members such as crankshafts, etc. In particular, this invention is directed to cooling fins for dissipating heat generated in vibration dampers of the type having an inertia member mounted on a hub by an intermediate elastic member.
Crankshafts of internal combustion engines occasionally vibrate at certain engine speeds due to the forces generated in engine operation. This engine vibration, unless damped, can cause breakage of the crankshaft. In order to avoid such vibration, it is frequently the practice to add a torsional vibration damper to the end of the crankshaft.
In modern practice, such dampers take the form of a hub member mounted on the crankshaft and an inertia member mounted on the hub member by means of an intermediate elastic vibratory movement energy-absorbing and dissipating element. Examples of this type of damper may be found in U.S. Pat. No. 2,477,081 to Peirce and U.S. Pat. No. 3,670,593 to Troyer. The mass of the inertia member is so selected in conjunction with the resiliency of the elastic element that it is put in vibration in opposition to the vibration of the crankshaft whenever the crankshaft vibrates in tune. In this manner, it acts to dampen out the torsional vibrations in the crankshaft through a hysteresis effect in the elastic element. Typically, the elastic element is made of rubber material. Unfortunately, a great amount of heat is generated within the rubber or elastic element during operation. This heat can cause degradation and failure of the elastic element, requiring frequent replacement thereof.
In order to avoid this, torsional vibration dampers have been constructed with integral fins on the inertia member. An example of this type of construction is found in U.S. Pat. No. 3,314,304 to Katzenberger et al. However, the great amount of heat generated within the elastic element is not sufficiently dissipated by these integral fins.